1. Field of the Invention
The invention relates to an injector, in particular a common rail injector, for injecting fuel into a combustion chamber of an internal combustion engine.
2. Description of the Prior Art
From European Patent Disclosure EP 1 612 403 A1, an injector embodied as a common rail injector is known, having an axially pressure-balanced control valve (servo valve) for blocking and opening a fuel outflow conduit from a control chamber. By means of the control valve, the fuel pressure inside the control chamber can be varied, and the control chamber is constantly supplied with fuel at high pressure, via an inflow throttle restriction. By varying the fuel pressure inside the control chamber, an injection valve element is adjusted between an open position and a closed position, and in its open position the injection valve element enables the fuel flow into the combustion chamber of an internal combustion engine. The control valve includes a sleevelike control valve element, which is adjustable in the axial direction by means of an electromagnetic actuator and which is guided on a guide bolt embodied in one piece with a valve piece. The sleevelike control valve element, with its inside circumference, defines a valve chamber, embodied at a reduced-diameter portion of the guide bolt, of the control valve radially outward only, so that no opening or closing forces from the fuel at high pressure act on the control valve inside the valve chamber. On the face end of the control valve element, there is a sealing line, which cooperates in sealing fashion with a control valve seat disposed on the valve piece. The diameter of the sealing line is equivalent to the guide diameter of the control valve element, and the guide diameter is equivalent to the outside diameter of the guide component, plus a minimal play. Because of its pressure equilibrium, the control valve is suitable for switching very high pressures. A disadvantage of the known injector is the heavy burden on the linear sealing edge upon closure of the control valve, which can lead to not inconsiderable wear at the sealing line.